Field
The disclosure relates to a biosensor, and more particularly to a reduced graphene oxide-based biosensor. The disclosure also relates to a method for detecting an analyte using the biosensor.
Background Information
Recently, biosensors have been used widely for diagnosis of various diseases. In particular, nano-scaled biosensors, such as nanowire field effect transistor (FET)-based biosensors, made from semiconductor nano materials have gained much attention due to their advantages, such as high sensitivity, high selectivity, and fast analysis.
Graphene sheets have a high surface area and superior conductivity, and thus are often used for modifying FET. However, as graphene sheets lack functional groups for the immobilization of biomolecules (for example, antibodies), it is difficult to directly use graphene sheets in FET-based biosensors. Therefore, recently more investigations have been focused on the modification of graphene sheets used in FET-based biosensors so as to promote the immobilization of biomolecules onto graphene sheets.
It has been disclosed in the art, for example, Materials Chemistry and Physics, vol. 136 (2012), p 304-308; and Nanoscale, 2013, vol. 5, p 3620-3626, to modify the graphene sheets used for FETs using the Hummers' method so as to obtain a modified graphene sheet including short-chain carboxylic groups each having one carbon atom. Each of the short-chain carboxylic groups included in the modified graphene sheet is used for bonding a receptor specific to an analyte so as to produce a FET-based biosensor. However, the amount and the bioactivity of the receptors contained in the biosensor thus produced are relatively low due to the fact that the chain length of the short-chain carboxylic groups is relatively short.
There is a need in the art for a biosensor with receptors that are higher in amount and bioactivity of receptors as compared to the aforesaid biosensor which is produced from a graphene sheet modified by the Hummers' method.